Electric signal system



J111Y 24 1934 c. c. FARMER E'l' AL ELECTRIC' SIGNAL SYSTEM Filed Aug. 8, 1927 ATTO NEY Patenfed .uy 24, 1934 UNITED STATES PATENT 01=F1es ELECTRIC SIGNAL SYSTEM Clyalc C. Farmer, Pittsburgh, and Thomas H. Thomas, Edgcwood, Pa., assignors to The Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application August8, 1927, Serial No. 211,348

4 Claims.

the station from which the signal was sent by the trainman or at any other station or stations the trainman may clj1oose.

Another object of the invention is to provide an electric train signal system for railway trains, in which thesources of electric current on the cars of the train are connected to ground only When the system is being.used in signalling.

In the accompanying drawings, Fig. 1 is a dia-L grammatic view of an electric signal system ernbodyingthe nvention and illustrating the enginemans switch in one poston; and. Figs. 2 and 3 are diagrammatic sectional vews illustrating the enginemans switch in two other positions.

As illustrated in the accompanying draiwings -the locomotive 'or controlled car of a train may be provided With an electric battery 1 or any other desirecl source of electric current, a signal indicating device such as a buzzer Zand an enginemans switch 3 comprising a rotatable member 4 which is provided With a contact 5 adapted in one position to electrically connect terminalcontacts 6 and. 7 Which are connected to ground at 8 and to one terminal of the buzzer 2, respectively, and in another position to electrically connect termi- -na] contacts 9 and 19, which are connected to the positive terminal of the battery 1 and to a train wire 11, respectively. The negative terminal of the battery 1 is connected to ground at 12. The train wire 11 is connected to the other terminal of the buzzer 2.

Each" of the cars of a train may be provided withan electric battery 12 or any other suitable source of electric current, a signal indicating device sch as a buzzer 13, a switch device 14 and a jack device 15.

The switch device 14 comprises a casing 16 containing a sliding contact member 17, which member is provided With an operating stem 18 adapted to be operated, in one direction, by a lever 19 having operatng arms 20 and. 21, each having an operating oord 22attached thereto. 19 is adapted to fulcrum around pins 23 and 24 whchare so disposed and mounted in the casing 16, that when the arm 20 is operated the lever turns about the pin 23 and when the arm 21 is oprated the lever turns about the pin 24 and in either case the lever depresses the stem 18 and the contact member 17, rotative movement of the member being prevented by a pin mounted in the The memberl7 is provided with contacts 25, 26

This lever and 27 and is normally maintained in the position shown in the drawings by the action of a spring 28. When the mex1iber 17 is moved a predetermined distance by the lever 19, the end of the member will engage and stop against a stop formed on a plug 29 having screw-threaded connection With the casing. When the member 17 is in this position the contact 25 connects terminal contacts3 and 31 in the casing, the: contact 30 being connected With the positive terminal of the battery 12 and the contact 31 being connected with one terminal of the signal indicating device 13 and the contact 27 connects terminal contacts 32 and 33, the contact 32 being connected to ground at 34 and the contact 33 beingconnected With the negative terminal of the battery 12. When the member 17 is in its normal position, as shown in the drawings, the contact 26 connects terminal contacts 35 and 36, the contact 35 being connected With a tine 37 of the jack 15 and the contact 37 being connected to ground at 34.

The jack 15is also provided With a tine 38 which is connected With the wire which connects the terminal contact 31 and the buzzer 13. The tines 37 and 38 of the jack are normally disconnected but are adapted to be connected by the insertion of a plug 39 between them.

Assuming the several parts of the signal system to be in the positions as shown in Fig. lofthe drawings, and the trainman desi1es to signal the engineman, the trainman polls the oord 22, which causes the lever 19 to operate to depress the stem 18 and contact member 17 to the position in which the contact 25 ccnnects the terminal contacts 30 and 31, and the contact member 27 connects the contact terminals 32 and 33. With the enginemans switch in the postion shown in the drawings an electric circuit is completed irom ground 34, contact 27, battery -12, contact 25, buzzer 13, train wire 11, buzzer 2 and contact 5 of the engnemans switch, to ground 8, and both buzzers 2 and 13 wil1 operate. If the tranman desires he may hold the contact member -17depressed, which causes the buzzers 2 and-13 to op erat until such time as the engineman, by the rotation of the contact member 1 of his switch causes the contact 5 thereof to open andclose the circuit, thus controlling the operation of ooth buzzers. It will th-us be noted th;t With this circuit, the trainman and the engineman may signal back and forth to each other as many times as necessary.

With the several parts of the signal system in the positions as shown in Fig. 1 of. the draw ings, and the trainman desires the system to be in readiness that he might receive, at his station on the train, any signal which might be initiated by the engineman, he inserts the plug 39 betWeen -the tines37 and 38 of the jack 15, thus causing one terminal of the buzzer 13' to be cennected threugh the jack and contact 26 te greund 34. New, f the engneman wishes te signal the trainman, he retates the member 4 te the pesitien shown in Fig. 3 of the drawings, in which pesitien, the contact 5 cennects the terminal centacts 9 and 10, which cempletes a circuit frem greund 8 threugh battery 1, contact 5, train wire 11, buzzer 13, jack 15 and contact 26 te greund 34. Should the trainman desire the enginemans signal te sound in all of the cars of the train, he inserts a plug 39 in each of the jacks 15.

It will here be noted that the trainmans switch, in its nermal positien as sheWn in the drawings, maintains beth terminals of the battery 12 discennected frem greund and from the remainder of the signal circuit, thus reducing te a minimum the pessibilities of short circuiting the leattery. The only time this battery is cennected te ground is when the trainman operates his switch te signal the engineman, i. e. when the contact member 17 is in its depressed positien.

Having now described eur invention, what we claim as new and desire te secure by Letters Patent, is:-

1. In a train signal system, a train signal circuit system including a train wire, a source of current on the power vehicle of the train having ene of its terminals cennected te greund, a signal indicating device on the power vehicle having ene of its terminals cennected te said train wire, a switch device en said vehicle fer cennecting the ether terminal of said source te said train wire and for connecting the ether terminal of said signal indicating device te greund, said switch device having an eperating zone in which the connectien from said train wire te said ether terminal of said source of current may be opened and clesed while the connectien frem the signal indicating device te greund remains epen, a signal indicating device on each car of the train having ene terminal cennected te said train wire, a source of current on each car, a hermally epen switch device on each car adapted te be clesed :to connect the ether terminal of the local car signal indicating device te greund, anether switch device en each car of the train operable te connect ene terminal of a lecal source of current te said ether terminal of the local signal indicating device and consequently te the train wire and te connect the ether terminal of the local source of current te greund.

2. In an electric signal system fer a train, a

plurality ei nermally epen signal circuits, a train ;wire censtituting a pertien of each 0 said circuits, a signal indicating device included in eachcircuit and having ene terminal cennected te the train wire, a source of electriccurrent fer said circuits having ene terminal cennected te ground and nermally discennected from said circuits, a normally open switch included in each of said circuits eperable tecennect the ether terminal of a lecal signal indicating device and consequently the train wire te ground, anether nermally epen circuit which includes said train wire, a. signal indicating device included in said circuit having ene of its terminals cennected to the train wire, a plurality of sources of electric current fer the last mentioned circuit normally discennected from the circuit, switch means for at ene time connecting the train wire te the ether terminal of said source of current and er at anether time connecting the ether terminal of the second mentioned signal indicating device te greund, said switch means having an eperating zone in which the connectien frem' said train wire te said source may be epened and clesed while the connectien from the signal indicating device te greund remains epen, and. when se operated opening and closing the circuit threugh the first mentioned source of current, train wire and signal indicating device which is cennected te greund by ene of the first mentioned switches, and said switch means when in pesition clesing the connectien from the second mentioned signal indicating device te ground maintaining the connectien frem the train wire te the first mentioned source of current epen, a switch device included in each of said plurality of circuits operable te connect ene terminal of the local source of current te greund and the ether terminal te the train wire, said switch device being eperable te epen and close the cennectiens from the local source of current te the train wire te centrel the eperatien of the secendmentiened signal indicating device when said switch means is in pesition te connect the second mentioned signal indicating device te ground.

3. In a train signal System, a signal circuit system including a train wire, a source of electric current en the power vehicle of the train, said source of current having ene terminal cennected te greund, a source of electric current en each car of the train, a signal indicating device en each car and having ene terminal cennected te the train wire, normally epen switch devices en the cars of the train adapted te be selectively clesed te connect the ether terminal of the local ear'signal device te greund, switch means en the power vehicle having an operating zone in which a cenneetienirem the ether terminal of the source of current en the power vehicle te the train wire may be epened and clesed te centrel the eperatien of the local car signal indicating device which is cennected te greund by the local switch device and having a pesitien fer cennecting the ether terminal of the signal indicating device en the power vehicle te greund while the cennectienjfrom the train wire te said source of current remains epen, and switch devices en said cars selectively eperalele te connect ene terminal of a lecal source of current te greund and the other terminal te the other terminal of the local car signal device and censequently te the train wire and eperable te epen and close the circuit through said local source of current train wire and signal indicating device en the power vehicle te cause the signal indicating device te eperate when said switch means is in pesition connecting the signal indicating device te greund.

4. In a train signal system, a train wire, a signal device en the power vehicle of the train cennected te said wire, a source of current en said vehicle cennected te greund, a switch device en said vehicle fer cennecting said source te said wire and fer cennecting said signal device te greund, said switch device having an eperating zone in which the connectien from said wire te said source may be opened and closed while the connectien from the signal device te greund remains epen, a signal device en each car of the train, each cennected te said wire, a source of current en each car, a switch device en each car having ene pesitien fer cennecting said lecal source of current te greund and te said train wire and anether pesitien fer cennecting said train wire te greund, while the connectien frem the local source te the train wire remains open.

CLYDE C. FARMER. THOMAS H. THOMAS. 

